// backend/jobs/reminderCron.js
 import cron  from 'node-cron';
 import pool  from '../config/mysqlPool.js';
 import { sendSMS } from '../utils/smsService.js';

const BATCH_SIZE = 25;

/* Every minute */
cron.schedule('*/1 * * * *', async () => {
  try {
    // IMPORTANT: use execute() so the param is truly bound

    const [rows] = await pool.execute(
       `SELECT id,
               phone_e164   AS toNumber,
               message_body AS body
          FROM reminders
         WHERE status      = 'pending'
           AND send_at_utc <= UTC_TIMESTAMP()
      ORDER BY send_at_utc ASC
         LIMIT ?`,
      [BATCH_SIZE]   // must be a number
     );

    if (!rows.length) return;

    let sent = 0, failed = 0;
    for (const r of rows) {
      try {
        await sendSMS({ reminderId: r.id, to: r.toNumber, body: r.body });
        sent++;
      } catch (err) {
        console.error('[reminderCron] Twilio error:', err?.message || err);
        failed++;
      }
    }
    console.log(`[reminderCron] processed ${rows.length}: ${sent} sent, ${failed} failed`);
  } catch (err) {
    console.error('[reminderCron] DB error:', err);
  }
});